Abstract: In order to study the variation of growth and development of maize ear, explore maize seed-setting rate and the reasons for the formation of barren ear tip, the author studied different varieties and cultivation conditions on the growth dynamics of maize ear. This paper used modern image processing techniques on two different fecundity of maize and studied the growth dynamic of maize ear, and determined ear length, ear diameter, barren ear tip length, ear volume, ear axis volume and ear kernels volume. The results showed: (1) From the beginning of the maize pollination to the maturity, the growth accorded with the Logistic equation simulation. (2) The dynamic change of ear length, ear diameter, ear volume, ear axis volume and ear kernels volume was from rapid growth to slow growth, showed that the time of ear diameter achieving the maximum growth rate was later, crops could effectively supply ear nutrient, and it made ear diameter increase. It could be seen from the change of volume that after anthesis 14 d, increasing in ear volume and ear kernels volume of the poor growing conditions’Shandan 902 was significantly slower, but Zhengdan 958’s still increased. This indicated that Shandan 902’s fecundity was poor, after anthesis 14d, slower growth in the ear kernels volume led to the formation of barren ear tip. (3) It could be seen from dynamic change of grain weight per ear, the ratio of dry ear kernels weight and dry ear weight, the ratio of ear kernels volume and ear volume that under different growth conditions that the growth trend of the same variety was consistent. Of the same variety, dry weight ratio of the treatment of good growing conditions was lower than poor growing conditions. Of the same variety under different growth conditions, the ratio of volume in good growing conditions was higher than that in the poor growing conditions. (4) From the ear yield and ear traits characteristic, it could be seen that the barren ear tip length of Shandan 902 was significantly higher than that of Zhengdan 958. Under four different treatments, the ratio of ear kernels volume and ear volume of Zhengdan 958 was higher than that of Shandan 902. To improve ear yield and prevent the occurrence of barren ear tip, management in anthesis 7~14 d must be enhanced.